献血员中TT病毒DNA检测及部分基因序列分析

Detection of TT virus DNA and sequence analysis of partial gene of TTV in sera from blood donors

目的探讨献血员中一种与输血后肝炎有关的病毒—ＴＴＶ的感染情况。方法采用ＴＴＶ基因组ＯＲＦ１区的套式聚合酶链反应（ｎｅｓｔｅｄ－ＰＣＲ）方法检测２６２份献血员血清标本。结果在血清丙氨酸转氨酶（ＡＬＴ）异常、ＨＢｓＡｇ及抗－ＨＣＶ阴性的５８份献血员血清标本中，１８份ＴＴＶＤＮＡ阳性，ＴＴＶＤＮＡ的阳性检出率为３１０％；在２０４份正常献血员血清标本中检出３０份（１４７％）ＴＴＶＤＮＡ阳性，ＴＴＶＤＮＡ的阳性检出率明显低于ＡＬＴ异常献血员人群（χ２＝３８１，Ｐ＜００５）。序列分析结果显示，其序列与日本株和中国株相应位置核苷酸序列的同源性大于９７％，可能属同一基因型。结论提示我国献血员中存在ＴＴＶ感染，ＴＴＶ存在“健康携带状态”。

In order to investigate TTV infection in blood donors, 262 sera samples from blood donors were detected by nested-PCR method using primers from ORF1 of TTV genome DNA. The results showed that 18 of 58(31 0%) serun samples from blood donors with elevated transaminase level were positive for TTV DNA. 30 of 204 (14 7%) sera samples from blood donors with normal transaminase levels were positive for TTV DNA. There were significant difference between them (χ 2=38 1,P<0 05). Five products of PCR for TTV DNA were purified and cloned to T Vector. The sequence analysis showed that there were above 97% nucleotide identity among AB008394 (from Japan),TTVCHNI(from China) and our 5 isolates from blood donors. The results suggest that there exists TTV infection among blood donors in China. TTV may be transmitted by blood transfusion. Our isolates, AB008394 and TTVCHN1 share a same genotype.